package test;

import java.util.Random;

public class test03 {
    public static void main(String[] args) {
        Random rand = new Random();
        String str="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
        StringBuilder yzm=new StringBuilder();
        for(int i=0;i<6;i++){
            int index = rand.nextInt(str.length());
            char ch=str.charAt(index);
            yzm.append(ch);
        }
        System.out.println(yzm.toString());
    }
}
